Hot top liner



Sept. 6, 1969 N. F. TISDALE, JR 3,

HOT TOP LINER Filed Dec. 14, 1966 INVENTOR.

NORMAN F. TISDALE,JR.

his ATTORNEY United States Patent 3,467,173 HOT TOP LINER Norman F. Tisdale, Jr., Valencia, Pa., assignor to Susquehanna Corporation, Chicago, Ill. Filed Dec. 14, 1966, Ser. No. 607,350 Int. Cl. B2211 7/10, 23/02 US. Cl. 164-339 4 Claims ABSTRACT OF THE DISCLOSURE A hot top for ingot molds. The hot top is provided with a liner comprising mitered slabs of exothermic material having top and bottom flanges extending outwardly less than 90 so as to form a snap fit with the interior top and bottom edges of the hot top.

This invention relates to a novel construction for a hot top to be used in a process for forming ingots from molten metal. More specifically, the invention relates to the construction of a hot top casing and exothermic slab to provide a snap-fit inter-relation.

Hot top liners are commonly used in steel production for the purpose of reducing a funnel shaped contraction in the head of the ingot, known as pipe. By insulating or exothermically heating the contracting head, the hot top reduces pipe as well as center segregation and porosity, sometimes called fishtails. Hot tops must be frequently relined with exothermic slabs after they are burned out by the molten metal.

Hot tops may consist of clay molds, ceramic sleeves within refractory casings or, more commonly, metal casings with an interior layer of insulating or exothermic material bonded to the casing.

The main disadvantages of presently used hot tops is that they are diflicult and time consuming to assemble for use or to reline with new material. Unless this relining is done by a workman having considerable skill, leakage, floating, and uneven cooling will result, thereby causing unnecessary scrap in the further processing of the ingots. When skilled workmen are used to make the hot tops, the costs of relinin g are usually high.

A principal object of the present invention is to provide a very efficient hot top that is extremely simple to assemble, install and reline.

Another important object is to provide a hot top which affords cost savings through simplicity in construction and easy and quick assembly and disassembly.

A more specific object of the invention is to provide a specially shaped, snap-fitting exothermic slab that can be easily attached to a variety of hot top casings.

Other objects and advantages will become apparent from a study of the following description taken with the accompanying drawing wherein:

FIG. 1 is a perspective view of a hot top embodying the present invention;

FIG. 2 is a perspective view of one of the slabs of exothermic material preshaped for use in the hot top of FIG. 1;

FIG. 3 is a cross sectional view taken along line III-III of FIG. 1; and

FIG. 4 is a fragmentary perspective view showing the hot top inserted in and supported by an ingot mold.

Referring more particularly to FIG. 1 of the drawing, the novel hot top embodying my invention, generally denoted by numeral 1, comprises a rigid metal (or refractory) casing 2 having a plurality of walls 3, preferably inclined upwardly and outwardly.

As best seen in FIGS. 2 and 3, the slightly flexible exothermic slabs 6 comprise end flanges and 7 which "ice snugly fit above shoulder 4 and below base 9 of the hot top casing, respectively. The exothermic flanges 5 and 7 are slightly cambered to the normal angle to provide a snap-fit connection to hold slab 6 securely against the top and bottom edges of the hot top only by spring action and friction without the need of special binders, Wedges, or other kinds of fasteners normally required. The side edges are beveled at a 45 angle so as to form a miter joint with other slabs. It should also be noted that exothermic slab 6 completely shields walls 2 from the molten metal by enclosing the walls on three sides (see FIG. 3) with top and bottom flanges 7 and 5 which are an integral part of the exothermic slab.

After the exothermic slab is burned away by the intense heat of the poured molten metal, another set of exothermic slabs can be quickly and easily snapped into place by inserting them through the bottom of the hot top and turning them slightly to enclose the side walls.

Lugs 8 are provided on the casing so as to be supported on the top of the mold as shown in FIG. 4, also so that the casing may be moved or removed from the ingot mold either manually or by means of a crane attachment. Moreover, instead of suspending the casing 2 in the mold, by making the base larger, it may rest entirely on top or above the top surface of the mold.

While I have shown the casing 1 in FIG. 1 as having a slight taper, it may be desirable to have vertical sides, instead. Also, it should be noted that the novel exothermic slab construction can be adapted to fit casings having a variety of shapes.

Thus it will be seen that I have provided an eflicientexothermic slab which is very slightly flexible and having snap-fitting edge flanges to enable quick and easy attachment and detachment from the hot top casing, and which will completely screen the casing from the molten metal poured into the mold.

While I have illusthated and described several embodiments of my invention, it will be understood that this is by way of illustration only, and that various changes and modifications may be made within the contemplation of my invention and Within the scope of the following claims.

I claim:

1. A hot top for ingot molds, said hot top having substantially vertical walls and an interior liner comprising slabs of exothermic material having cambered top and bottom flanges which form a snap-fit with interior top and bottom edges of said walls.

2. A hot top liner as recited in claim 1 wherein said hot top is entirely supported by the top edge of said ingot mold.

3. A hot top as recited in claim 1 wherein said hot top walls have lugs on their outer faces to facilitate moving or supporting said hot top.

4. A hot top as recited in claim 2 in combination with an ingot mold, said hot top is fitted into the top portion of said ingot mold and supported on the top of said mold by said lugs so that a substantial portion of said walls is contained within said ingot mold.

References Cited UNITED STATES PATENTS 1,137,264 4/1915 Gathmann 249-106 3,060,533 10/1962 Marbury 249-108 X 3,092,883 6/1963 Ednell 249-199 3,265,347 8/1966 Wickstrom 249-197 X 3,344,838 10/1967 Nouveau 249-200 X I. SPENCER OVERHOLSER, Primary Examiner I. S. BROWN, Assistant Examiner US. or. X.R. 

